[NEW BUG]: Reduce allocations in sun.reflect.annotation.AnnotationInvocationHandler.invoke()

[Christoph Dreis]

Hey,

I'm new to the OpenJDK and not sure (yet) how the procedure especially for
new bugs/enhancement is. So I apologise upfront if I made any mistakes.

I'm working mostly with the Spring-Framework/Spring-Boot in my current
projects. In these frameworks a lot of dynamic proxying can happen.
Recently, I noticed that the JDK in versions 8 up to the current snapshots
produces some allocations coming from
sun.reflect.annotation.AnnotationInvocationHandler.invoke() we could avoid
in the majority of cases. Only the check for equality needs the actual
parameter types - all other cases only need the parameter count which JDK 8
luckily provides with Method.getParameterCount().

What about changing the current behaviour to something like my attached
proposal? I'd be happy if someone is willing to sponsor this change. Again -
if I made any mistakes here, please let me know for the next time.

Cheers,
Christoph Dreis